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Title: Synthesis of Naphthalimidedioxime Ligand-Containing Fibers for Uranium Adsorption from Seawater

Journal Article · · Industrial and Engineering Chemistry Research
 [1];  [1];  [2];  [1];  [1];  [1];  [3];  [4];  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division
  2. Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry
  3. Supramolecular Design Institute, Oak Ridge, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical Sciences Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Chemistry

Uranium exists as uranyl carbonates (primarily as [UO2(CO3)3]4-) at a low concentration of 3.3 ppb, in seawater. Due to the ocean's vast volume, the total amount of uranium in seawater has been estimated at 4.5 billion tons or nearly 1000 times more than land-based resources. This large surplus provides attractive solution to supply nuclear fuel feeds in future. However, the presence of a variety of competing metal ions and the low concentration of uranium in seawater make the extraction of uranium from seawater challenging. The goal of this work is to develop adsorbent fibers that can recover uranium from the slightly alkaline (pH 8.0 - 8.3) seawater. In this process, radiation-induced graft polymerization (RIGP) is used where fibers are prepared by irradiating and treating polyethylene (PE) with different bulk ratios of vinyl benzyl chloride (VBC) and methacrylic acid (MAA) or itaconic acid. Furthermore, chemical modifications of these fibers were performed via two step processes, where novel bisimidoxime ligands are incorporated into fibers. These ligands contain imidedioxime, which is known to be a uranium-philic functionality. Also, the core structures of these ligands containing three donor atoms facilitate the formation of chelates with uranyl ion in seawater. Density functional theory (DFT) calculations were performed to quantify the binding strength with the uranyl ion. The adsorbent showed moderate to high uranium (~35-50 g-U/kg adsorbent) adsorption capacity in a model seawater with a uranium concentration of 6 ppm at pH 8.0 8.3.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE)
DOE Contract Number:
AC05-00OR22725; AC02-05CH11231
OSTI ID:
1248769
Journal Information:
Industrial and Engineering Chemistry Research, Vol. 55, Issue 15; ISSN 0888-5885
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English